1. Field of the Invention
The present invention relates to a call initiating system for mobile communication terminals including portable telephone units.
2. Description of the Prior Art
Today, the dissemination of mobile communication terminals including car telephones and portable telephones is truly significant, and their use is expanding, especially in big cities, from the business community to common house-holds. Supported by the remarkable development of LSI technology and digital processing technology, these mobile communication terminals are becoming ever more compact and more sophisticated functionally. In terms of compactness, units comparable to ordinary telephone sets are already available, and their unit size is predicted to be reduced to about 100 cc in the near future and further to a wrist watch size eventually. In the functional aspect, existing models already have the abbreviated dialing or one-touch dialing function for use with frequently accessed communication partners and the automatic redialing function for use when the other party's line is found busy at the first call attempt, and an even greater variety of functions are likely to be added in the future along with the further sophistication of networks.
Although progress is recognized in these aspects of mobile communication terminal technology, it seems difficult to introduce a fundamental renovation in the technique for call initiation by the calling subscriber, i.e. in the currently used call initiation by dialing. However, as the use of telephone communication will further expand along with the development and globalization of economic and business activities, the current method of searching a personal memo or the telephone directory for the other party's telephone number and the dialing on that basis will become too inefficient, and are likely to be replaced in the future by retrieval from a data base within the mobile communication terminal itself, utilizing LSI technology and data base technology.
In order to enable the telephone number to be retrieved from the data base within the mobile communication terminal of the aforementioned wrist watch size and a call to be initiated by the retrieved number, the space occupied by the data display means, such as an LCD display, and the call initiating means, such as dialing keys, should be minimized.